1. Field of the Invention
The present invention relates to a liquid cartridge that is mounted on a liquid ejecting apparatus to supply liquid to a liquid ejecting head. More particularly, the present invention relates to an ink cartridge that is mounted on an ink-jet recording apparatus to supply ink to a recording head of the ink-jet recording apparatus.
2. Description of the Related Art
An ink cartridge as an exemplary liquid cartridge for supplying ink to an ink-jet recording apparatus as an exemplary liquid ejecting apparatus holds the ink therein. The ink cartridge supplies the ink to a recording head of the ink-jet recording apparatus by being mounted onto the main body of the ink-jet recording apparatus, so as to record information such as characters, images and the like, on a recording medium such as paper.
FIGS. 1A and 1B are a perspective view of the aforementioned ink-jet recording apparatus 10 and an approximately front view thereof showing an ink transfer path 203.
In the ink-jet recording apparatus 10 shown in FIGS. 1A and 1B, the ink transfer path 203 connects a plurality of ink cartridges 300 mounted on a cartridge holder 200 to a carriage 201. Ink accommodated in each ink cartridge 300 is supplied to a recording head 205 that is provided on the carriage 201 and can be moved together with the carriage 201, through a flexible tube serving as the ink transfer path 203 by request from the carriage 201.
More specifically, the ink-jet recording apparatus 10 shown in FIGS. 1A and 1B includes the main body 100 and the cartridge holder 200 provided in a part of the main body 100, on which the ink cartridges 300 are to be mounted. The cartridge holder 200 has a cover 202 that is pivotable in a direction indicated with a double-headed arrow in FIG. 1A. An example of the ink-jet recording apparatus 10 is a large-sized ink-jet printer that can perform recording for large-sized paper (A2 size to A0 size, for example) such as poster, by using a large amount of ink. The ink-jet recording apparatus 10 supplies the ink in the ink cartridge 300 incorporated in the cartridge holder 200 to the recording head 205 mounted on the carriage 201 through the ink transfer path 203 such as a flexible tube, as shown in FIG. 1B, and causes the recording head 205 to emit the ink while the carriage 201 is being scanned, thereby performing the recording for paper supplied to the ink-jet recording apparatus 10.
With the scan of the carriage 201 in the scanning direction (horizontal direction in FIG. 1B) during the printing operation, the ink transfer path 203 is bent and extended. Such extending and bending of the ink transfer path 203 causes the ink in the ink transfer path 203 to flow in a direction of ink supply toward the carriage 201 (hereinafter, referred to as a forward direction) or in the opposite direction to the forward direction. The ink flow in the forward direction or backward direction causes the ink in the flexible tube of the ink transfer path 203 to apply positive or negative pressure to the recording head 205.
As the ink cartridge 300 used in this type of ink-jet recording apparatus 10, an ink cartridge has been proposed that has a check valve for allowing ink flow in the ink supply direction but preventing ink flow in the opposite direction to the ink supply direction. In a case of this type of ink cartridge 300, with the extending and bending of the ink transfer path 203, the ink is supplied from the ink cartridge 300 to the recording head 205 when the flow velocity is given in the ink supply direction, whereas the check valve is arranged to completely close the ink flow path in the ink cartridge 300 when the flow velocity is given in the opposite direction to the ink supply direction. Thus, in a case of using the conventional check valve, the ink cannot flow back from the recording head 205 to the ink cartridge 300. In the ink-jet recording apparatus 10 using the ink cartridge 300 having the check valve of the above structure, when the extending/bending of the ink transfer path 203 described above is repeated during the printing operation, the ink is oversupplied to the recording head 205, which may cause an ink drop to fall from a nozzle of the recording head 205. Moreover, in a case where the moving speed of the carriage 201 is increased to increase the printing speed, the ink pressure may be increased to damage the recording head 205.
On the other hand, as another type of conventional ink cartridge, an ink cartridge is known that has a supply valve in a channel in which the ink cartridge is connected to the ink-jet recording apparatus 10, in order to allow ink to be supplied while the ink cartridge is connected to the ink-jet recording apparatus 10 and to prevent the ink from leaking to the outside while the ink cartridge is not connected to the ink-jet recording apparatus 10.
In such an ink cartridge, however, air from the outside may get into an ink accommodating part of the ink cartridge when a user forcedly opens the supply valve to the outside by using a projection such as a pen tip. Once the air got into the ink accommodating part, even if the ink cartridge has been mounted onto the ink-jet recording apparatus 10 thereafter, the air may obstruct the ink flow in the ink flow path. In addition, when air bubble reached the recording head 205, it may prevent ink emission from the nozzle, that is, may cause dot defect, leading to defective printing. As a result, the ink may not be supplied in an appropriate manner even if the ink cartridge is connected to the ink-jet recording apparatus 10.